Well, a couple things. I never really liked Power Rangers that much. I mean I watched the first season and enjoyed it on a small level, but I could never get too into it. I also feel it isn't fun enough to be cheesy, and it's not serious enough to be taken seriously. So it's an unhappy medium with me. And lastly, I'm more of an Ultraman guy.
That said, I do not doubt it has a huge fanbase over the age of 10. I mean, you can't punt a football in a web forum without hitting a PR fan of some sort. Even still, an animated version of the show has as much appeal as the animated Fraggle rock. it seems like a good idea, you can get away with a little more in animation than in live action, but other than that... what's the point? other than continuing the franchise, it seems like all the charm of something done in live action is gone. Plus, other little factors in making a cartoon play a role in making it not as memorable as the original.
I mean, I think an animated show would work, but I just don't see it being as successful as the live action series, unless the same people are involved.